Roll feeder



March 7, 1933.

J.H.MQRROW ROLL FEEDER Filed June l5 'INVENTOR .l/i/hZMZFZWV BY 0 WM W ATTORNEY Patented Mar. 7, 1933 UNITED STATES PATENT? DFFICE JOSEPH H. kOBBOW, OI HOKENDAUQUA, PMSYLVANIA, ASBIGNOB TO FULLER GOI- PANY, A COBPOBAJIION O1 DELAWARE nournanaa Application fled June 1:,

' andretain air and inthis condition an apparently dense mass may assume the ,characteristics of a thin liquid. This is frequently caused by a'slide of material or the collapse of an arch formed at or near the bottom of a storage bin, which causes air to mix with the lowermost materials in storage, due to the pressure or head of materials abovethe arch. This condition may be aggravated by the use of compressed air to overcome the friction between the mass of material and the walls of the bin in order to cause the material to discharge freely.

These aerated materials under pressure head or at a difference in level will discharge through very small openings, and may attain almost the same level in an adjacent container, to which the storage bin may be connected. Screw, star and roll feeders, of which I am aware, although satisfactory for the handling of relatively coarse materials cannot handle fine materials either without flooding or at a reasonably uniform rate.

The lack of uniformity of feeding of the usual star or roll feeders is further aggravated by the tendency of materials to become wedged or packed in the pockets so that they do not discharge freely. Wear and power requirements are excessive, as material tends to pack between the ends of the roll and the walls of the feeder casing.

In accordance with the resent invention, both sides of the roll are. e ectively sealed by the material itself, and a symmetrical arrangement rmits rotation of the roll in either direction. The pockets are filled uniformly without wedging or packing and at the discharge orifice they are emptied completely, together with any dust that might tend to accumulate between the ends of the low casing havin mi. Serial :0. 544,121.

roll and the walls of the casing. The parts are arranged to avoid actual contact of metal surfaces with the roll in order to reduce wear and means are provided to maintain the seal, as the parts become worn due to the abrasive effect of'the material handled. I

The invention comprises in general a hola material opening protected by renewab e wearing surfaces, having sharply inclined inner walls, to permit the free flow of material downwardly toward the roll. The end walls of the casing are'provided with a substantially circular recess of a diameter slightly larger than the roll, which 15 mounted for rotation upon a shaft supported in outboard bearings beyond the walls of the casing. The rollis preferabl a steel casting of relatively thin section or elasticlty, and 1s provided with closely spaced longitudinal pockets, the cross-section of whlch is preferably less than a semi-circle, to reduce their tendency to retain material when inverted. The pockets extend lengthwise slightlybeyond the lower edge of the wear lates, In order to permit close clearances tween the roll and the upper portion of the end-walls of the casing to avoid discharge of aerated materials at the ends of the roll. A The roll is supported by a central disc cast mtegrallvand provided with an enlarged sleeve at its center, which is keyed to the shaft. Each end of the roll is closed preferably b roll is ot erwise hollow, and its inner surface 18 irregular and preferably conforms substantially to the curvature of the pockets. One or more balls of iron or other heavy material resting freely within the roll and dropping from one low point to another during rotation serves to discharge the ockets completely. The inner surface of the roll is slightly inclined from the center, to cause the balls or weights also to rap against the thin discs at the ends to prevent the accumulation of dust, which is discharged through recesses fgrmefi in the end-walls belowv the center of In order to fill mares aasaa,,nd seal, follower plateauto effect the material provided at each side of the roll. These plates are preferably similar and their inner surfaces conform in curvature to the roll,

' but are spaced a slight distance from it to prevent actual contact of metal to metal, this distance being variable as hereinafter described. The depth of the plates is suflicient to cover at least two pockets to maintain the seal and to prevent a free discharge of material. Thefollowers are provided with sharp leading edges to scrape and cause the pockets to fill uniformly without wedging. The upper edge of each follower plate is enlarged and provided with a bore to receive a supporting shaft, to which it is keyed. 'This shaft circular the ends of the roll 9. v The roll. is preferably plate, and the uniform filling and dischargextends through stufling boxes. preferably at each end of the casing and levers of a preciablelengthare connected at their en s by a coil spring to maintain the plates in normal position.

Sto s are arranged to prevent the springs from rawing the plates into contact with the roll, the stops being made adjustable in order that the proper clearance may be maintained and to compensate for wear. A further purpose of the coil ring is to prevent injury to the feeder or riving mechanism by foreign materials such as tramp iron, which may be caught in the pockets, as the follower plate may swing outwardly to'discharge' this mat-. ter. The side walls of the casing are flared outwardly to permit the follower plate to swing through a considerable arc.

The sharp leading edge of the follower Fig. 2,

ig. 2 is a cross-section on line 2-2 of Fig.1, and

Fig. 3 is a rear elevation.

Referring to the drawing, the apparatus is seen'to consist of a casing having a frontwall 1, an end wall 2 and outwardly flared side walls 3 and 4. The upper portion of the'casing is provided with a flanged inlet 5 and the lower portion with outlet 6, for the material handled. ,7

The end walls 1 and 2 are provided with 7 and 8, arranged to receive made of cast steel'of relatively thin section and includes a central, integrally cast disc 10,v provided with'a sleeve 11, having acentral bore, ,the roll bein keyed for rotation as at 12 to the drive sha 13. The drive shaft passes through stufling boxes 14 and 15 in the end walls 1 and 2 and is so ported in outboard bearings 16 and 17 a igned on brackets 18 and19, preferably cast integrally with the end wal In order to girotect the inlet from abrasion,

at the point 0 greatest wear, renewable members 20 and 21 are secured to the end walls 1 and 2. These members have sharply inclined inner surfaces to permit a free flow of material toward the roll. They are curved to conform to the latter and overhang the ends of the roll to hinder the entrance of material between the ends of the roll and the walls of the casing.

The ro longitudinal pockets 22, which extend slightly beyond the lower edges of the members 20 and 21. The cross-sectlon of the pockets 22 is preferably less than a half circle, in order to overcome the tendency of materials to bind or bridge and remain in the ockets after the latter pass the discharge orifice. The inner surface of the roll 9 is irregular and preferably corresponds in curvature to the ckets,

l is provided with closely spaced in order that weights 23 and 24, which may" be cast-iron balls or other heavy material, may drop from high points as 25 to low points 26 during rotation of the roll.

As the roll is preferably made of cast steel of relativel thin section, it is sufiiciently elastic to vi rate slightly fro the droppmg of the weights, to dlscharge he material at the outlet 6, the slight drop of the balls being insuflicient to set up unfavorable vibration which might injure the bearing surfaces or-accessory equipment.

The thickness of the roll 9 decreases from the center toward the ends in order to cause the balls 23 and 24 to rap against relatively thin steel plates 27 and 28, which close the end of the roll and are accommodated in recesses therein.

Below the level of the shaft 13, the inner surfaces of the end walls 1 and 2 are further recessed as at 29 and 30, in order to form a free discharge for materials which would otherwise accumulate between the ends of the roll and the walls. The occasional ra ping of the balls 23 and 24 against the thin steel discs 27 and 28 loosens the material and causes it to discharge freely through the recesses 29 and 30.

At the inlet, the inner surfaces of the side walls 3 and 4 incline downwardly as at 31 and 32 and are reversely curved at 33 and 34 to conform to the ends of follower plates 36 and 37, these plates being keyed to shafts 38 and 39. The shafts 38 and 39 pass through stufling boxes 40 and 41, arranged in the end walls land 2, where they are keyed to arallel levers 42 and 43. a

\ relatively heavy coil spring 44 connects l varying quantities and the rate of handling lit? plat

the ends of the crank arms. 42 and 43 and maintains them and likewise the follower plates 36 and 37 in their innermost positions, the tension of the spring 44 being variable by means oi the screw hooks as at 45.

The upper inner surfaces 46 and 47 of the follower plates are inclined downwardly toward the roll and form extensions to the inner snr'face of the 'lhe lower por .tion of? e surfaces of the follower a as at and 49 to conform to the roll 9, and are of a depth to cover at least two 22 in order to form a seal of material to prevent flooding. The follower plates are provided with shar leading, edges 50 and 51, one of which, epending on the direction of rotation of the roll 9, serves to scrape excess material across the poclrets,-so that the latter are filled with a uniform quantity of material without wedging or packing the latter. The leading edges 50 and 51 are preferably protected by a weer-resisting alloy, such as that commonknown as stellite, to prevent rounding of 1 these edges dne to abrasion. The spaces hetween pockets are preferably likewise pro.

tected. l have found that rounded leading edges tend to wedge or pack material in the pockets with the result that the latter fill at is further varied by the tendency of material to stick to the surfaces of the roll.

In order to prevent actual contact between inner surfaces 48 and 49 and the outer surface of the roll 9, adjustable stops are provided as indicated particularly in Fig. 3. These ma comprise bolts 52 and 53, which are three ed in bosses 54 and 55 on the in-- ner sides of levers42 and 43. The heads of these bolts may abut bosses 54 and 55, cast integrally with the end walls 1 and 2. By this means, any desired clearance between the follower plates and the roll may be maintained and compensation made for wear of the parts.

As the levers, stops and connections are arranged similarly beyond each end wall, 1 and 2, only one end has been shown and described in detail.

In the preferred form of my invention, as

described, the follower plates are similar andtheir related operating parts are identical, but it is to he understood that one of these plates might he fixed or simply adjustable;-

or thet the lever and spring tension device might be emitted at one end of the casing to obtain many of the advantages of my invention over the prior art and without depart ing from the spirit of the invention, a

In ration, my apparatus may be installed w low a hm or conveyor, so that the prevent urchin of material above the roll and permit a uni orm deposit in each pocket, which is scraped at a constant level without packing, y the leading edge 50 or 51 of the follower plate, depending upon the direction of the rotation of the roll 9. As the lower surfaces 48 and 49 of the follower plates are held closely adjacent to and conform to the curvature of the roll, aerated material cannot leak or flood toward the discharge outlet, as the weight of material is evenly deposited upon the roll, and as the ockets are shallow, the material seal formed y the covering of two'pockets prevents the common tendency of most roll feeders to spin after the power has been shut off, due to the weight or head of material or for the roll to run at a greater rate than desired.

As the follower plates are held at their innermost positions, under the heavy tension of the coil spring 44, the roll is sealed at each side. Tramp iron or other foreign material, of large enough size to injure the parts, is discharged by outward movement of the follower plate on the operating side, the latter returmng to its normal position immediately aitetg the pocket has cleared the end of the p a 4 I In view of the above, it will be evident that this feeder has a high volumetric eficiency, and as the pockets are filled with uniform quantities, without wedgingthe density remains constant, so that the weight of materialsdischarged may be calculated with very slight error. Accordingly, a simple revolution counter, as indicated at 56, may be conled tothe driven'shaft 13, as at 5?, to callrate the feeder.

I claim:

l. A feeder iorhandlingfine materials at a uniform rate, comprising the combination of a casin having an inlet and an outlet, a hollow roli arranged for rotation between the inlet and the outlet, the surface of the roll being provided with pockets of uniform size to receive the material, a follower plate closing one side of the inlet movably mounted near one side thereof having a portion or its inner surface conforming to the curvature of the roll, and of a depth suficient to cover at least two pockets, means normally maintain= ing the follower plate in an inward position near the wriace of the roll, the roll having an irregular inner surface and a relatively thin section and provided with circumferential channels at the ends of the roll, the ends or the roll heing closed by thin discs, and balls freely movable in said channels within the roll to engage and vibrate both the latter and the discs. I

2. A feeder for handling fine materials at a uniform rate, comprising the combination of a casing having an inlet and an outlet, a hollow roll arranged for rotation between the inlet and the outlet, the surface of the lie rec

lee

roll being provided with pockets of uniform size to receive the material, a follower plate closing one side of the inlet movably mounted near one side thereof, having a portion of its inner surface conforming to the curvature of the roll, and of a depth sufficient to cover at least two pockets, means normally maintaining the follower plate in an inward position near the surface of the roll, the roll having an irregular inner surface and a relatively thin section and being supported on a driven shaft by a central disc dividing the roll into two compartments, the thickness of the roll decreasing from the central disc toward thin discs which close the ends of the roll, and a ball in each compartment, freely movable therein and normall contacting both with the inner surface of t 'e roll and the end disc of said compartment, said ball vibrat ing both the roll and the disc as it moves around during rotation of the roll.

3. A feeder for handling materials at a uniform rate, comprising the combination of a casing having an inlet and an outlet, a hollow 'roll arranged for rotation between the inlet and the outlet, the surface of the roll being provided with closely spaced ockets of uniform size to receive the materlal, similar follower plates arranged at each side of the roll 1 and mounted at their upper edges near the inlet for swmglng movement, each follower plate having a portion of its inner surface curved to conform to the roll and of a depth sufficient to cover. at least two pocketsthereof,

means normally maintaining the follower plates in inward positions near the roll, the roll being supported on a driven shaft by a central disc cast integrally with the roll, and dividing the latter into two compartments,

- the roll being of relatively thin section, de-

creasing in thickness toward the ends, and having an lrregular surface conformlng substantially to the curvature of the pockets, the

ends of the roll being closed by relatively thin discs, and a ball freely movable in each compartment, said ball normally contacting with both the roll andthe end disc of its compartment during rotation of the roll, said ball being effective to vibrate the pockets and the disc.

4. A feeder for handling fine materials at a uniform rate, comprising the combination a of a casing havm an inlet and an outlet, and

cover at least two pockets, said surface having a shar leading edge, the roll being provided with c osely spaced longitudinalpockets of uniform size and having a central supporting disc dividing it into two compartments and secured to a driven shaft, the latter passing ter toward the ends, a ball freely movable in. each compartment and engaging both the roll and the end disc of said compartment to vibrate the pockets and the disc.

5. A feeder for handling fine materials, which comprises a casing having and walls and sloping side wall surfaces definin an inlet hopper, the end walls being provlded with circular recesses, a hollow roll arranged for rotation below said hopper and extending into the recesses, the roll belng provided with pockets of uniform size to receive the material, a pair of plates mounted in the casing at opposite sides of the roll, each plate having a sloping portion serving as a continuation of one of said sloping Wall surfaces of said hopper, and a curved portion conforming to the curvature of the roll and extending around the latter to an extent sufficient to cover at least two pockets in the surface of the roll, at least one plate being mounted to swing around the top edge of its $10 ing portion as a center toward and away rom said roll, means acting on said plate and resiliently forcing, it toward the roll, the roll having a a relatively thin, elastic section and an irre lar inner surface, the ends of the roll being closed by discs, the end wallsof the casing being provided with outlet recesses communicating with but extending below the first named recesses, and movable weights within the roll actuated by the irregular surface to vibrate the pockets and discharge material therefrom and to vibrate the discs to discharge material accumulating in the first named receses through the last named recesses. a

In testimony whereof I'afiix mysi ature.

JOSEPH H. MOR OW.

side of the inlet, secured at their upper edges to shafts supported for rotation in and pass ing. through the end walls of the casing, both ends of each shaft being provided with arms, spring means connecting the arms at each end of the casing, eachfollower plate having a portion of its surface conforming to the curvature of the roll and of a depth sufficient w 

